function [pre, rec] = computePR(resp, score, posclass, alpha)

% returns the precision and recall coordinates of an ROC curve 
% for a vector of classifier predictions, scores, given true 
% class labels, labels, and the positive class label and alpha
% level. 

[pre, rec] = perfcurve(resp, score, posclass, 'XCrit', 'ppv', 'Alpha', alpha);

end